C310 means scanner carriage problem (the moving light thing under the glass). 85% of call service codes are erroneous, which will reset readily by opening and closing the front door and/or switching the power switch off/on. Since those things are easier than posting here, I will assume that you've tried that and the code came back. I'm sorry to say there is no easy and common problem to have you check. The service info tells you to check the contact of the connector terminals (related electrical componant wiring), the home position sensor, the main PCB, and the scanner motor. You should also look into the glass to look for the drive cables at the front and rear to see if they are strung properly (not good if there is a mess of cables there). I can not remember ever seeing that code on that model, so I'm a little at a loss to even guess. You may need to get a tech to look at it. If you can add any info I'll check back.
Dave
DaveH, September 2007